The present disclosure relates to an illumination optical system and an image projection apparatus including the illumination optical system and a projection optical system.
A projector (image projection apparatus) has been known in the past, which includes an illumination optical system (illuminating unit) with a light source configured of a halogen lamp, a metal halide lamp, etc., and a projection optical system (projection unit) including an optical modulator, a projection lens, etc. (see Japanese Unexamined Patent Application Publication No. 2011-2611).
In recent years, a small (palm-sized) and lightweight portable projector known as a microprojector is beginning to be widely used in such a projector field. In such a microprojector, a light emitting diode (LED) is mainly used as a light source of an illuminating unit. Furthermore, recently, a laser has been noticed in light of expansion of a color reproduction range and reduction in power consumption.